Magnetic lifting and material transferring devices



Sept. 29, 1959 H. J. SJOSTROM MAGNETIC LIFTING AND MATERIAL TRANSFERRINGDEVICES Filed Aug. 29, 1958 3 Sheets-Sheet 1 III] I [III I!!! l- FIG. 3.

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H. J. SJOSTRQM MAGNETIC LIFTING AND MATERIAL TRANSFERRING DEVICES FiledAug. 29, 1958 3 Sheets-Sheet 2 FIG.

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MAGNETIC LIFTING AND MATERIAL TRANSFERRING DEVICES Filed Aug. 29, 1958 3Sheets-Sheet 3 FIG. 9.

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United States Patent MAGNETIC LIFTING AND MATERIAL TRANSFERRING DEVICESHarold J. Sjostrom, Pueblo, Colo. Application August 29, 1958, SerialNo; 757,992 Claims. (Cl. 294-655) This invention relates to materiallifting and transfer devices, and more specifically, the instantinvention pertains to material lifting and transfer means of a magneticyp One of the primary objects of this invention is to provide a materiallifting and transfer device employing one or more permanent magnetstogether with means for releasing materials lifted and transferred bysaid device.

Another object of this invention is to provide a permanent magnet typeof material elevating and transfer device, the permanent magnets beingembedded within a base formed of a non-magnetic material.

A further object of this invention is to provide a permanent magnetmaterial elevating and transfer device, together with means foreffecting the release of the material from the magnets, the means beinginterposed between the magnets and the material and being formed of anon-magnetic material.

Still another object of the invention is to provide a permanentmagnet-type material lifting and transfer device together with materialrelease means which is operable to move the material attracted to themagnets out of the magnetic field thereof to effect its. release fromthe device.

This invention contemplates, as a still further object thereof, theprovision of a material elevating and transfer device of the permanentmagnet-type, the device being non-complex in construction and assembly,inexpensive to manufacture, and durable in use.

Other and further objects and advantages of the instant invention willbecome more manifest from a consideration of the annexed drawings, whenread in conjunction with the following specification, in which:

Figure l is a perspective view of a magnetic-type material elevating andtransfer device constructed in acoordance with the teachings of oneembodiment of this invention;

Figure 2 is a detail cross sectional view, partly in elevation, takensubstantially on the vertical plane of line 22 of Figure 1, looking inthe direction of the arrows;

Figure 3 is a detail cross sectional view, partly in elevation, Figure 3being taken substantially on the vertical plane of line 33 of Figure 2,looking in the direction of the arrows:

Figure 4 is a bottom plan view of'the device illustrated in Figure l; v

Figure 5 is a top plan view of a second embodiment of a material liftingand transfer device constructed in accordance with this invention;

Figure 6 is a side elevational view of the modification shown in Figure'5;

Figure 7 is an end elevational view of the material elevating andtransfer device according to the second embodiment thereof, F igure 7being partially broken away to illustrate certain component elements ofthe device;

Figure 8 is a perspective view of a third embodiment of the instantinvention;

Figure 9 is an enlarged detail cross sectional view, part- 2,905,554Patented Sept. 29, 1959 2 ly in elevation, taken substantially on thevertical plane of line 9-9 of Figure 8, looking in the direction of thearrows;

Figure 10 is a perspective view of the device illustrated in Figure 8,Figure 10 illustrating the relative positions of the component elementsof the device to effect material release; and

Figure 11 is an enlarged fragmentary detail cross sectional view takensubstantially on line 1111 of Figure 10 looking in the direction of thearrows.

Referring more specifically to Figures 1 to 4, inclusive, referencenumeral 20 designates, in general a permanent magnet type materiallifting and transfer device constructed in accordance with the teachingsof one embodiment of this invention. As illustrated in these figures,the device 20 is seen to comprise a substantially cylindrical solid mainbody portion or casing 22 provided with a plurality of radially spacedbores 24 and a centrally positioned bore 26, the bores 24, 26 extendingtransversely through the main body portion 22 from the top and bottomends thereof.

Disposed within each of the bores 24 is a substantially cylindricalbar-type permanent magnet 28, the lower ends of the magnets 28 beingflush with the bottom end of the main body portion 22 while the upperends thereof terminate flush with the lower end of a cylindrical recess30. A discoidal cover plate 32 having a central aperture 34 is receivedwithin the recess 30 and substantially fills the same with the aperture34 being coaxially aligned with the bore 26.

The permanent magnets 23 may be press-fit or otherwise fixedly securedwithin their respective bores 24 or they may be otherwise fixedlysecured therein by conventional means. Conventional means is alsoemployed to fixedly secure the circumferential edge of the cover plateto adjacent areas of the main body portion 22. The latter, as well asthe cover plate 32, are formed of non-magnetic material such as, forexample, lead or brass. If preferred, the magnets 28 could be molded orcast in the main body portion 22.

To the upper sides of the main body portion 22 and the cover plate 32 issecured two pair of substantially diametrically opposed uprightstandards 36 with the standards of each pair being laterally spaced fromeach other, each'pair of the standards 36 having fixedly secured thereonand extending therebetween the opposed ends of pivot pins 38, and eachof the latter are loosely received within elongated slots 40 formed in apair of elongated actuating levers 42 adjacent one of their respectiveends.

Reference numeral 44 denotes an elongated substantially cylindricalshaft which is mounted for reciprocation through the bore 26 andaperture 34. As is clearly seen in the drawings, two pair ofsubstantially diametrically opposed lugs 46 project outwardly from theshaft 44 and disposed at the upper end thereof. The lugs 46 arelaterally spaced from each other to receive and support the opposed endsof a pair of pivot pins 48. The pivot pins 48 pivotally connect theaforementioned one ends of the actuating levers 42 to the shaft 44. Tothe lower end of the shaft 44 is fixedly secured a discoidal shield 50which is adapted, when in operative position, to fit flush across thelower ends of the magnets 28 and main body portion 22. Integral with theupper end of the shaft 44 is an open eye 52, the function of which willbecome more apparent below. The shaft 44 and the shield 50 are alsoformed of a non-magnetic material.

Reference numeral 54 denotes a flexible cable that terminates in aclosed loop 56 which is received within the open eye 52 of the shaft 44.The other end of the cable54 is trained about a pulley of a crane orother hoist (not shown) in such a manner that the operator thereof maypay out or reel in the cable 54 in exercising the functions of thedevice 20.

As is clearly shown in Figure 3 of the drawings, the other ends of thelevers 42 are apertured at 58 to receive therethrough closed loops 60formed at one of the ends of the pair of flexible cables 62. The otherends of the cables 62 are joined by a connector 64 which is, in turn,connected to one end of a cable 66 the other end of the cable 66 isfitted over a pulley or drum of a conventional crane or hoist, in themanner described above, whereby the same may be payed out or reeled inunder the control of an operator.

Referring now more specifically to Figure l of the drawings, the cable54 is under tension and has drawn the shaft 44 upwardly through the bore26 until the shield 50 abuts the lower end of the main body portion 22.The levers 42 have pivoted to their full line position illustrated inFigures 1 and 2 in the absence of tension of cable 62. The operator nowmanipulates the crane or hoist from which the device 20 depends to aposition over the magnetizable material to be moved vand pays out bothcables 54 and 66 until the shield 50 engages thereagainst. The magneticfields of the permanent magnets 28 causes the material to adhere againstthe underside of the shield 50 and the cables 54 and 66 are then reeledin to effect an elevation of the magnetized material, care beingexercised in reeling in the cable 66 to avoid tensioning the cables 62.The elevated magnetized material is moved to the site at which the sameis to be deposited, and upon reaching this position, the operator reelsin the cable 66 to such an extent as to cause the cable 62 to moveupwardly therewith. As the cables 62 move upwardly, the levers 42 pivotabout their respective pins 38 to force the main body portion 22 to moveupwardly relative to the shaft 44 thereby separating the shield 50therefrom, the shield 50 assuming the dotted line position indicated inFigure 3 of the drawings. The degree of movement between the shield 50and the main body portion 22 is of such extent to move the magnetizedmaterial out of the magnetic field to permit the same to drop from theshield 50 onto the desired transfer site.

The operator then returns the device 10 into a position over the nextload of material to be transferred and lowers the device 20 downwardlyinto engagement therewith. The shield 50 first engages the material, andthe cables 54 and 66 are payed out until the component elements of thedevice 20 assume their relative positions as is illustrated in fulllines in Figures 1 to 3, inclusive. Thereafter, the lifting and transferoperation is repeated as described supra.

Figures 5 to 7, inclusive, illustrate a second embodiment of thisinvention wherein reference 100 designates, in general, a magneticmaterial lifter and transport device constructed in accordance with theteachings of a second embodiment of this invention. The device 100 isseen to comp-rise a substantially cylindrical main body portion orcasing 102 formed of a non-magnetic material such as,.for example, leadorbrass and having fixedly embedded therein a centrally disposedcylindrical permanent bar magnet 104 having its longitudinal axiscoaxially aligned with the longitudinal axis of the main body portion102. As is seen in Figures 6 and 7, the lower end of the main bodyportion 102 is formed with a circumferential bevel .106 to serve afunction to be described, and the main body portion 102 has formed,integral with the upper end thereof, a pair of upright standards 108which receive and support therein the opposed ends of a pivot pin 110which extends therebetween.

Pivotally mounted on the pin 110, between the standards 108, are a pairof sleeves 112 to which are fixedly secured, respectively, a pair ofelongated actuating levers 114 intermediate their respective ends. As isseen in 74 I the above referred to figures, the ends 114A of the levers114 are loosely engaged within vertically elongated slots 116 formed inthe upper ends of a pair of vertically elongated, diametrically opposed,substantially rectangular bars 118 mounted for reciprocation withinvertically spaced pairs of lugs 120 which are integral with or otherwiserigidly secured to the main body portion 102. The bars 118 have a lengthgreater than the longitudinal axis of the-main body portion '102, and tothe lower ends thereof is secured a shield 122 which may be formed ofstainless steel, soft or low carbon steel, brass, or of other suitableand related materials.

As is seen in Figures 6 and 7, the shield 122 is recessed at 124 in sucha manner as to provide a beveled side 126 adapted, under' one conditionof operation of the device, to mate against the beveled end 106 of themain body portion 102.

To the ends 114A of the levers 114 are secured one of the ends of a pairof flexible cables 128 (shown in dotted lines), the other ends of whichare connected to a common flexible cable 130, the tension of which iscontrolled by the device operator to serve a function to be described.To the other ends 114B of the levers 114 are secured one of the ends ofa pair of flexible cables 132 (shown in dotted lines), the other endsthere- 'of being connected to a common lifting cable 134 (shown indotted lines in Figure 7).

The cables 130, 134 are reeved over hoist pulleys (not shown) and arereeled on drums controlled by an operator. vAssuming that the device andits component elements are in the full line positions shown in Figure 6,and that the device is suspended over magnetizable material which is tobe lifted and transported-to a new site, the cable 130 is reeled in toraise the ends 114A of the levers 114 to effect the closing of theshield 122 against the lower end of the main body portion 102 and thepermanent magnet 104. Thereafter, the cables 130, 134 are payed outsubstantially simultaneously until the shield 122 engages the materialto be lifted. The cables 128, 130 are then reeled in and the device 100is moved to the site at which the material is to be deposited.Thereafter, the operator increases the tension on the cables 132, in thedirection of the arrows, causing the ends 114B of levers 114 to pivotupwardly about the pivot pin to effect an elevation of the main bodyportion 102 relative to the shield 122. The relative movement of themain body portion 102 with respect to the shield 122 is of a sufiicientdistance to diminish the efiective magnetic field to such an extent asto permit the material adhering to the shield 122 to be releasedtherefrom and to drop into the new site.

Figures 8 to 11, inclusive, illustrate a third embodiment of thisinvention generally identified by reference numeral 200. The device 200is seen to comprise a substantially solid cylindrical main body portionor casing 202 formedof a non-magnetizable material in which are embeddeda plurality of cylindrical permanent bar magnets 204 which are radiallyspaced from one another. While the lower ends of the permanent magnets204 are substantially flush with the end of the main body portion 202,the upper ends of the bar magnets 204 do not extend flush with the upperend of the main body portion 202. The cavity thus formed is filled withthe metallic cap 206 formed of a non-magnetizable material. The mainbody portion 202 is formed with a central bore 208 and a coaxial uprightintegrally formed hollow boss 210. The boss 210 is provided with anaxially extending key slot 212 which, at its lower end, is in opencommunication with one end of an axially extending key groove 214. Theflange 218 is adapted to engage against the upper end of the boss 210 tolimit the down- .ward movement of the shaft 216.

Mounted for reciprocation through the bore 208 is an elongated shaft 216having a radial flange 218 adjacent the upperend thereof. The shaft 216is provided with a key 220 adapted to reciprocate within the key slot212 and the key groove 214. The upper end of the shaft 216 is providedwith an axially extending passage 222 which, at its lower end, is inopen communication with a diametrically extending passage 224. Theradial flange 218 is adapted to abut against the upper end of the boss210 in order to limit the downward movement of the shaft 216.

The lower end of the shaft 216 is necked down at 226 to receive thereona substantially cylindrical flat centrally apertured shield 228, formedof the same material as the previously described shield. The shield 228is provided with a plurality of radially extending circumferentiallyspaced reinforcing ribs 230 which are adapted to seat within grooves 232formed in the lower end of the main body portion 202.

At diametrically opposed points, the main body portion 202 isconstructed with tapped openings 234 which receive the threaded ends ofa pair of screws 236 to the upper ends of which are rigidly mounted ayoke 238 having opposed side walls 240, 242. The side walls 240, 242support therebetween the opposed ends of a pair of pivot pins 244 onwhich are rotatablysupported, respectively, a pair of pulleys 246.

One of the ends 248 of a pair of cables 250 are flexibly secured to theupper end of the shaft 216 by conventional means, and the other endsthereof are reeved around the pulleys 246 and are connected together bycoupler 252 to a common cable 254.

Reference numeral 256 denotes a cable having an end thereof extendingthrough the passage 222 and bent to extend through either end of passage224, this end of the cable 256 being knotted at 258 to prevent itswithdrawal from the shaft 216.

Assuming that the component elements of this embodiment of the inventionare in their operative positions as is illustrated in Figure 8, thedevice 200 is lowered to effect engagement of the shield 228 with themagnetizable material to be transported. Thereafter, the device 200 iselevated with the magnetizable material held against the shield 228under the influence of the mag netic fields of force generated by thepermanent magnets 204. When the device 200 has been moved to apreselected site, the operator places increased tension on the cable 254which, in turn, increases the tension on the cable 250 and drives thepulleys 246. As the pulleys 246 are driven the main body portion 202 iselevated relative to the shield 228. The extent of the movement of themain body portion 202 is suflicient to remove or diminish the magneticfield generated by the magnet 204 which previously exercised theirinfluence on the material adhering to the shield 228. Consequently, thematerial is released from the shield 228 and falls under the force ofgravity to the preselected site. The cables 250 are then released toreturn the main body portion to its operative position relative to theshield 228.

The sequential order of the operation of the above described embodimentsof this invention need not necessarily be followed in order to obtainthe release of the magnetizable material.

For example, in all cases, the cables 62, 32 and 50 could be placedunder tension to cause the main body portion 22, 102 and 202 to moverelative to their respective shields 50, 122 and 228, where conversely,the main body portions could be held stationary and the cables 50, 130and 256 could be released to prevent the shields 50, 122 and 228 to movedownwardly relative thereto under the force of gravity until thematerial adhering thereto has moved out of the magnetic field,

Having described and illustrated three embodiments of the instantinvention, it will be understood that the same are offered merely by wayof example, and that the instant invention is to be limited only by thescope of the appending claims.

What is claimed is:

l. A magnetic lifting device for magnetizable materials comprising acasing having embedded therein means for generating a magnetic field, ashield mounted on said casing, said shield being normally disposed insaid magnetic field intermediate said first means and said magnetizablematerial, and means on said casing connected with said shield to effectmovement of said shield toward and away from said casing.

2. A magnetic lifting device for magnetizable materials comprising asubstantially cylindrical main body portion, said main body portionhaving a bore extending transversely therethrough, a shaft mounted forreciprocation within said bore and projecting beyond a pair of opposedends of said main body portion, a plurality of bar-type permanentmagnets disposed within said main body portion and circumferentiallyspaced around said bore, a pair of spaced standards fixedly secured toone end of said main body portion on diametrically opposed sides of saidbore, a lever for each pair of said standards, means pivotallyconnecting each of said levers between said standards, means pivotallyconnecting one end of each of said levers to said shaft adjacent one endthereof, a shield extending across the other end of said main bodyportion, a lifting cable connected with said one end of said shaft forlifting said device, and a tripping cable connected with the other endof each of said levers, said tripping cable being operable to eifectpivotal movement of said levers and consequent relative movement betweensaid main body portion and said shield.

3. A magnetic lifting device for magnetizable materials comprising anelongated substantially cylindrical main body portion formed of anon-magnetic material, an elongated substantially cylindrical bar-typepermanent magnet embedded within said main body portion, said main bodyportion having a pair of standards projecting from one end thereof indiametrically spaced relation, a pivot pin mounted on and extendingbetween said standards, a pair of levers connected intermediate theirrespective ends on said pivot pin, a substantially cylindrical shieldadapted for extension across the other end of said main body portion, apair of bars having one of their respective ends connected to saidshield at diametrically opposed points, a pair of axially spaced lugsprojecting laterally from said main body portion on diametricallyopposed sides thereof, said bars being positioned for reciprocationwithin said pairs of lugs, each of said bars at their other respectiveends having an opening extending transversely therethrough, each of saidlevers having one of their respective ends loosely received in one ofsaid openings, a lifting cable connected with said one end of saidlevers to close said shield against said other end of said main bodyportion and to effect a lifting of said device, and a tripping cableconnected to the other ends of said levers, said tripping cable beingoperable to effect relative movement between said shield and said mainbody portion.

47 A magnetic lifting device for magnetizable materials comprising asubstantially cylindrical main body portion having a centrally disposedtransversely extending bore, a plurality of permanent magnets of thebar-type embedded within said main body portion in circumferentiallyspaced relation relative to said bore, a shaft mounted for reciprocationin said bore, a shield connected with one end of said shaft and beingadapted to extend across one end of said main body portion, meansadjacent the other end of said shaft for limiting the movement thereofin one direction, means for preventing relative rotation between saidmain body portion and said shaft, a pair of diametrically opposedpulleys fixedly secured on the other end of said main body portion, acable reeved around each of said pulleys and having one end thereoffixedly secured to the other end of said shaft, said cable comprising atripping cable, and a lifting cable having one of its ends fixedlysecured to said other end of said shaft, said lifting cable beingoperable to close said shield against said main body portion of saiddevice and to lift said 7 shield and said main body portion as a unit,and said tripping cable being operable of effect relative movementbetween said main body portion and said shield.

5. A magnetic lifting device for magnetizable materials comprising anelongated casing having a pair of opposed ends, a bar magnet embeddedwithin said casing and having an end thereof substantially flush withone of said opi posed ends, a closure member extending across said oneend of said casing, said closure member being formed of a non-magneticmaterial, and means supported on the other end of said casing forefiecting relative movement be: tween said casing and said closuremember.

References Cited in the file of this patent UNITED STATES PATENTS o,WWWM

